Drive device

ABSTRACT

In a drive system, there is provided a waste heat recovering device forming a Rankine cycle by an evaporator for heating water with waste heat of an internal combustion engine to generate high-pressure vapor, the internal combustion engine being connected to a transmission, a displacement-type expander for converting high-pressure vapor generated by the evaporator to an output with constant torque, a condenser for liquefying low-pressure vapor discharged from the expander, and a feed pump for supplying water liquefied by the condenser to the evaporator. The expander is connected to a power generator/motor via a planetary gear mechanism, and the expander is connected to an output shaft of the internal combustion engine via the planetary gear mechanism and a belt-type continuously variable transmission. A change gear ratio of the belt-type continuously variable transmission is controlled such that a rotational speed of the internal combustion engine and a rotational speed of the expander are matched with each other and are transmitted to the transmission. Hence, it is possible to effectively drive the driven portion by using the output of the expander of the waste heat recovering device.

This application is the national phase under 35 U.S.C. § 371 of PCTInternational Application No. PCT/JP00/08702 which has an Internationalfiling date of Dec. 8, 2000, which designated the United States ofAmerica.

FIELD OF THE INVENTION

The present invention relates to a drive system which is comprised of awaste heat recovering device including a displacement-type expander anda power transmission system for transmitting the output of the expanderto a driven portion.

BACKGROUND ART

Japanese Patent Publication No. 7-35846 discloses an exhaust energyrecovery apparatus which is comprised of a turbine driven by exhaust gasof an internal combustion engine, a power generator driven by theturbine, a motor driven by power generated by the power generator, and aplanetary gear mechanism for combining the shaft output of the motorwith the shaft output of the internal combustion engine. According tothe exhaust energy recovery apparatus, it is possible to recover a partof energy of exhaust gas that has been conventionally discarded withoutbeing effectively used so as to assist the shaft output of the internalcombustion engine, thereby contributing to a reduction in consumption offuel.

It should be noted here that the above conventional device suffers froma problem that kinetic energy of exhaust gas is used to drive theturbine and hence, thermal energy of high-temperature exhaust gas cannotbe effectively used, resulting in low efficiency of recovering energy.Thus, it has been considered that exhaust energy is recovered by aRankine cycle comprised of an evaporator for heating water by usingthermal energy of exhaust gas to generate high-pressure vapor, anexpander for conversing high-pressure vapor, which is supplied from theevaporator, to shaft output with constant torque, a condenser forliquefying low-pressure vapor discharged from the expander, and a feedpump for supplying water liquefied by the condenser to the evaporator.In this case, a displacement-type expander is adopted, so that it ispossible to obtain high efficiency in a wide rotational speed region ofthe expander, thereby more effectively recovering energy of exhaust gas.

When a displacement-type expander is adopted in an waste heat recoveringdevice of a Rankine cycle type, the shaft output of the expander hastime delay relative to the shaft output of the internal combustionengine. In addition, the expander is characterized by shaft output withconstant torque and a rotational speed determined by shaft output of theinternal combustion engine. Therefore, in order to effectively use theshaft output of the expander, it is necessary to provide a special powertransmission system, which is suitable for the above describedcharacteristics, between the expander and a driven portion driven by theexpander.

DISCLOSURE OF THE INVENTION

The present invention is achieved in view of the above describedcircumstances and an object thereof is to effectively drive a drivenportion by using an output of an expander of a waste heat recoveringdevice forming a Rankine cycle.

In order to attain the above object, according to the present invention,there is provided a drive system which comprises a waste heat recoveringdevice forming a Rankine cycle by an evaporator for heating a workingmedium with a waste heat of a prime mover to generate a high-pressurevapor, a displacement-type expander for converting high-pressure vaporgenerated by the evaporator to output with constant torque, a condenserfor liquefying low-pressure vapor discharged from the expander, and apump for supplying a working medium liquefied by the condenser to theevaporator; and a power transmission system for transmitting the outputof the expander to a driven portion, the power transmission systemdriving the driven portion according to the output characteristics ofthe expander.

With the above arrangement, regarding the expander of the Rankine cycleusing a waste heat of the prime mover as a heat source, the outputcharacteristics include time delay relative to the output of the primemover, and changes in rotational speed with constant torque relative tochanges in output of the prime mover. The power transmission systemdisposed between the expander and the driven portion drives the drivenportion according to the above output characteristics of the expander,so that the output of the expander can be effectively used.

Further, in addition to the above arrangement, there is provided a drivesystem, wherein the power transmission system drives the driven portionwithin a range of the output characteristics of the expander.

With the above arrangement, since the power transmission system drivesthe driven portion within a range of the output characteristics of theexpander, it is possible to prevent the expander from operating beyondthe range of the output characteristics and reducing efficiency.

Moreover, in addition to the above arrangement, there is provided adrive system, wherein the power transmission system can distribute theoutput of the expander to a plurality of driven portions in an arbitraryratio.

With the above arrangement, since the power transmission systemdistributes the output of the expander to a plurality of driven portionsin an arbitrary ratio, the output of the expander can be applied for avariety of uses to enhance general-purpose utility.

Moreover, in addition to the above arrangement, there is provided adrive system, wherein the power transmission system comprises at least aplanetary gear mechanism.

With the above arrangement, since the power transmission systemcomprises the planetary gear mechanism, the output of the expander canbe properly distributed to a plurality of driven portions.

Besides, an internal combustion engine 1 of an embodiment corresponds tothe prime mover of the present invention, and a power generator/motor124 and a transmission 143 correspond to the driven portions of thepresent invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 to 24 show an example of the present invention, wherein FIG. 1is a diagram showing an overall configuration of a drive system; FIG. 2is a diagram showing a structure of a driving force transmission system;FIG. 3 is a diagram for explaining matching of a shaft output of aninternal combustion engine and the shaft output of an expander; FIG. 4are graphs showing a relationship between a rotational speed and shaftoutput of the internal combustion engine and a relationship between arotational speed and shaft output of the expander; FIG. 5 is a graphshowing a relationship between a rotational speed of the internalcombustion engine and a rotational speed of the expander; FIG. 6 is agraph showing changes with time in rotational speed of the internalcombustion engine, rotational speed of the expander, and change gearratio of a belt-type continuously variable transmission; FIG. 7 is avelocity diagram of a planetary gear mechanism at a start of theinternal combustion engine; FIG. 8 is a velocity diagram of theplanetary gear mechanism when the expander is not operated after theinternal combustion engine is started; FIG. 9 is a velocity diagram ofthe planetary gear mechanism at the start of the expander; FIG. 10 is avelocity diagram of the planetary gear mechanism during steady statedriving; FIG. 11 is a velocity diagram of the planetary gear mechanismduring acceleration of the internal combustion engine; FIG. 12 is avelocity diagram of the planetary gear mechanism during deceleration ofthe internal combustion engine; FIG. 13 is a diagram for explaining theoperation of the planetary gear mechanism when climbing load is applied;FIG. 14 is a velocity diagram of the planetary gear mechanism when theexpander is started by a power generator/motor; FIG. 15 is alongitudinal section showing the expander (sectional view taken along aline 15—15 in FIG. 18); FIG. 16 is an enlarged sectional view showing aneighborhood of a rotation shaft of FIG. 15; FIG. 17 is a sectional viewtaken along a line 17—17 in FIG. 15; FIG. 18 is a sectional view takenalong a line 18—18 in FIG. 15 with an enlarged essential portion; FIG.19 is an explanatory drawing showing a section of a rotor chamber and arotor; FIG. 20 is a front view showing a vane body; FIG. 21 is a sideview showing the vane body; FIG. 22 is a sectional view taken along aline 22—22 in FIG. 20; FIG. 23 is a front view showing a seal member;and FIG. 24 is an enlarged view showing a neighborhood of the rotationshaft of FIG. 17.

BEST MODE FOR CARRYING OUT THE INVENTION

The mode for carrying out the present invention will now be described byway of an embodiment with reference to the accompanying drawings.

FIGS. 1 to 24 show an embodiment of the present invention.

In FIG. 1, a waste heat recovering device 2 of an internal combustionengine 1 as a prime mover installed in an automobile, has an evaporator3 for generating a vapor with raised temperature and pressure, that is,high-pressure vapor by using waste heat such as exhaust gas of theinternal combustion engine 1 as a heat source, an expander 4 forgenerating shaft output by expanding the high-pressure vapor, acondenser 5 for liquefying vapor which is discharged from the expander 4with a dropped temperature and pressure after the expansion, that is,for liquefying low-pressure vapor, and a feed pump 6 for supplyingliquefied working medium such as water from the condenser 5 to theevaporator 3. A displacement-type expander with constant output torqueis used as the expander 4. The displacement-type expander 4 hasexcellent efficiency at all rotational speeds, and the rotational speedis determined by a quantity of vapor generated by the evaporator 3. Avariety of structures are available for the displacement-type expander4, and a vane-type expander 4 is adopted in the present embodiment. Thestructure of the vane-type expander 4 will be specifically discussedlater.

As is apparent from FIG. 2 at the time of simultaneously referring toFIG. 2, a power transmission system 121 connected to the waste heatrecovering device 2 comprises a planetary gear mechanism 122, abelt-type continuously variable transmission 123, and a powergenerator/motor 124, which forms a driven portion of the presentinvention.

The planetary gear mechanism 122 comprises a sun gear 125, a ring gear126, a planetary carrier 127, and a plurality of planetary gears 128which are supported on the shaft of the planetary carrier 127 and areengaged simultaneously with the sun gear 125 and the ring gear 126. Theplanetary carrier 127 connected to an output shaft 129 of the expander 4can be engaged with a casing (not shown) by a carrier brake 130. The sungear 125 connected to an input/output shaft 131 of the powergenerator/motor 124 can be engaged with a casing (not shown) by a sungear brake 132. The ring gear 126 can be engaged with a casing (notshown) by a ring gear brake 133. The carrier brake 130, the sun gearbrake 132, and the ring gear brake 133 are each formed by a hydraulicbrake or an electromagnetic brake.

The power generator/motor 124 is connected to a battery 134 which can becharged and discharged. The power generator/motor 124 charges thebattery 134 when the power generator/motor 124 is driven by the shaftoutput of the expander 4 or the internal combustion engine 1 to functionas a power generator, and the power generator/motor 124 assists a drivenwheel driven by the internal combustion engine 1 or starts the internalcombustion engine 1 when the power generator/motor 124 is fed from thebattery 134 to function as a motor.

The belt-type continuously variable transmission 123 comprises a drivepulley 136 provided on an input shaft 135, a follower pulley 138provided on an output shaft 137, and an endless belt 139 wound aroundthe pulleys 136 and 138. The drive pulley 136 and the follower pulley138 are each varied in groove width by hydraulic control or electriccontrol. When the drive pulley 136 is increased in groove width and thefollower pulley 138 is reduced in groove width, a change gear ratiovaries to the LOW side continuously or in a stepless manner, and whenthe drive pulley 136 is reduced in groove width and the follower pulley138 is increased in groove width, a change gear ratio varies to the TOPside continuously.

A drive gear 140 provided on the ring gear 126 of the planetary gearmechanism 122 is engaged with a driven gear 141 provided on the inputshaft 135 of the belt-type continuously variable transmission 123. Theshaft output of the internal combustion engine 1 is transmitted to atransmission 143, which forms a driven portion of the present invention,via an output shaft 142, and the output of the transmission 143 istransmitted to a driven wheel (not shown). A drive gear 144 provided onthe output shaft 137 of the belt-type continuously variable transmission123 is engaged with a driven gear 145 provided on the output shaft 142of the internal combustion engine 1.

Torque limiters 146 and 147 are provided respectively on the outputshaft 129 of the expander 4 and the input/output shaft 131 of the powergenerator/motor 124. The torque limiters 146 and 147 slip when torque ofa predetermined value or more is applied to the expander 4 or the powergenerator/motor 124, thereby preventing the occurrence of overload. Thetorque limiters 146 and 147 can be replaced with clutches which aredisengaged in the event of torque causing overload of a predeterminedvalue or more. A clutch 148 is provided on the output shaft 137 of thebelt-type continuously variable transmission 123. The clutch 148 isprovided to prevent driving force, which is inversely transmitted fromthe internal combustion engine 1 or the driven wheel, from causingoverload applied to the expander 4. The clutch 148 connects the internalcombustion engine 1 and the expander 4 upon engagement and disconnectsthe internal combustion engine 1 and the expander 4 upon disengagement.

Thus, when the sun gear brake 132 of the planetary gear mechanism 122 isengaged to fix the sun gear 125, the planetary carrier 127 and the ringgear 126 each serve as an input element or an output element, drivingforce input from the expander 4 to the planetary carrier 127 is outputto the ring gear 126, and the driving force is transmitted therefrom tothe output shaft 142 of the internal combustion engine 1 via the drivegear 140, the driven gear 141, the belt-type continuously variabletransmission 123, the drive gear 144, and the driven gear 145. Hence,the shaft output of the expander 4 can assist the shaft output of theinternal combustion engine 1. Meanwhile, in the case where the drivingforce is transmitted in reverse paths when the expander 4 is started,the expander 4 can be smoothly started with the shaft output of theinternal combustion engine 1.

Further, when the ring gear brake 133 of the planetary gear mechanism122 is engaged to fix the ring gear 126, the expander 4 or the powergenerator/motor 124 respectively serve as an input element and an outputelement, driving force input to the planetary carrier 127 from theexpander 4 is output to the power generator/motor 124 via the sun gear125, and the power generator/motor 124 is caused to function as a powergenerator to charge the battery 134. Meanwhile, in the case where thedriving force is transmitted in reverse paths when the expander 4 isstarted, the expander 4 can be smoothly started with shaft output of thepower generator/motor 124 serving as a motor.

Moreover, when the carrier brake 130 of the planetary gear mechanism 122is engaged to fix the planetary carrier 127, the sun gear 125 and thering gear 126 each serve as an input element or an output element.Therefore, driving force input to the sun gear 125 from the powergenerator/motor 124, which functions as a motor, is output to the ringgear 126, and the driving force is transmitted therefrom to the outputshaft 142 of the internal combustion engine 1 via the drive gear 140,the driven gear 141, the belt-type continuously variable transmission123, the drive gear 144, and the driven gear 145 so as to assist theshaft output of the internal combustion engine 1 and start the internalcombustion engine 1. Meanwhile, the shaft output of the internalcombustion engine 1 can be transmitted to the power generator/motor 124in reverse paths so as to cause the power generator/motor 124 tofunction as a power generator for charging the battery 134.

Next, referring to FIG. 3, the following will schematically discuss thefunctions of the waste heat recovering device 2 and the powertransmission system 121.

When a driver operates an accelerator pedal in response to requirementoutput necessary for driving of an automobile, the internal combustionengine 1 is operated, and thermal energy generated by the combustion offuel is partially converted to mechanical energy and is supplied to thetransmission 143 as an output shaft. In an ordinary internal combustionengine, the rest of thermal energy generated by the combustion of fuelis lost as thermal energy of cooling loss, friction loss, and exhaustgas without being effectively used. In the present invention, thethermal energy of exhaust gas is converted to mechanical energy by theexpander 4 of the waste heat recovering device 2. And then, the shaftoutput of the internal combustion engine 1 and the shaft output of theexpander 4 are combined in the power transmission system 121 and areoutput to the transmission 143. Thus, thermal energy of exhaust gas thathas not been conventionally used in an effective manner can beeffectively recovered, thereby contributing to a reduction inconsumption of fuel.

It should be noted here that the shaft output of the internal combustionengine 1 quickly responds to the operation of the accelerator pedal.Meanwhile, although thermal energy of exhaust gas discharged from theinternal combustion engine 1 quickly varies according to an operatingcondition of the internal combustion engine 1, the generation ofhigh-pressure vapor in the evaporator 3 has a time lag, resulting in atime lag between the shaft output of the expander 4 operated by thehigh-pressure vapor and the shaft output of the internal combustionengine 1. Additionally, the expander 4 has a relatively narrow range ofrotational speeds while the internal combustion engine 1 has arelatively wide range of rotational speeds. Therefore, when the shaftoutput of the internal combustion engine 1 is assisted by the shaftoutput of the expander 4, in the power transmission system 121, it isnecessary to absorb delay in response in change in rotational speed ofthe expander 4 relative to a rapid increase or decrease in rotationalspeed of the internal combustion engine 1, to absorb a difference inrange of rotational speeds between the internal combustion engine 1 andthe expander 4, and to properly match the rotational speed of theinternal combustion engine 1 and the rotational speed of the expander 4to effectively drive the transmission 143. For this reason, an outputrotational speed of the expander 4 is variably controlled by theplanetary gear mechanism 122 and the belt-type continuously variabletransmission 123 that are placed between the expander 4 and thetransmission 143.

Further, by fixing one of three elements of the planetary gear mechanism122, that is, one of the sun gear 125, the ring gear 126, and theplanetary carrier 127, the transmission of driving force can be switchedamong the expander 4, the power generator/motor 124, and the belt-typecontinuously variable transmission 123 (that is, the internal combustionengine 1), so that the expander 4, the power generator/motor 124, andthe internal combustion engine 1 can be effectively used for manypurposes.

FIG. 4 shows comparison between the output characteristics of theinternal combustion engine 1 and the output characteristics of theexpander 4. Since a torque of the internal combustion engine 1 isvariable, any shaft output can be obtained between an upper limit value(during full throttle) and a lower limit value (during idling) at anyrotational speed (see a diagonally shaded area of the left graph). Forexample, when the internal combustion engine 1 has a rotational speed of1500 rpm, the lower limit value of shaft output is 1 kW and the upperlimit value is 11 kW. Conversely, from the shaft output side of theinternal combustion engine 1, when the shaft output is 10 kW, arotational speed starts from 1300 rpm and reaches 5000 rpm, which is alevel limit. At this point, even when the internal combustion engine 1has a constant shaft output of 10 kW, since the rotational speed isvaried, a temperature of exhaust gas rises with higher rotational speed.Hence, a quantity of vapor supplied from the evaporator 3 to theexpander 4 also increases.

The right graph of FIG. 4 shows a plot of a rotational speed and shaftoutput of the expander 4 in accordance with various operating conditions(rotational speed and shaft output) of the internal combustion engine 1.For example, when the internal combustion engine 1 has a rotationalspeed of 1500 rpm and shaft output of 10 kW, the expander 4 has arotational speed of 600 rpm and shaft output of 1.5 kW. Moreover, whenthe internal combustion engine 1 has a rotational speed of 5000 rpm andshaft output of 10 kW, the expander 4 has a rotational speed of 1268 rpmand shaft output of 3.2 kW. In this way, when the operating conditionsof the internal combustion engine 1 are varied, the rotational speed andshaft output of the expander 4 change substantially along a straightline with a directly proportional relation.

The reason for the directly proportional relation between a rotationalspeed and shaft output of the expander 4 is that the displacement-typeexpander 4 has constant torque and only a rotational speed thereof ischanged according to an operating condition of the internal combustionengine 1. Namely, when a temperature of exhaust gas is changed accordingto an operating condition of the internal combustion engine 1, an amountof vapor generated in the evaporator 3 is changed, and a rotationalspeed of the expander 4 is changed according to the amount of thegenerated vapor. Meanwhile, since the expander 4 has torque of a fixedvalue, the shaft output of the expander 4, which is given as the productof a torque having a fixed value and a rotation speed having a variablevalue, is directly proportional to a rotational speed.

FIG. 5 shows a plot of a relationship between a rotational speed of theinternal combustion engine 1 and a rotational speed of the expander 4.The relationship is determined based on the left graph and the rightgraph of FIG. 4. For example, when the internal combustion engine 1 hasa rotational speed of 3000 rpm, the expander 4 has a rotational speed of430 to 1500 rpm. This is because when the internal combustion engine 1has a constant rotational speed but is varied in shaft output, atemperature of exhaust gas is varied to change an amount of vaporgenerated. Thus, a rotational speed of the expander 4 increases ordecreases accordingly.

As described above, it is found that a rotational speed of the expander4 and a rotational speed of the internal combustion engine 1 do not havea one—one relation, and the rotational speed of the expander 4 has apredetermined region of rotational speeds at each rotational speed ofthe internal combustion engine 1 (see a diagonally shaded area of FIG.5). A broken line in FIG. 5 shows matching between a rotational speed ofthe expander 4 and a rotational speed of the internal combustion engine1. The above described region is positioned on the lower right of thebroken line, and a rotational speed of the expander 4 is always lowerthan that of the internal combustion engine 1. Therefore, in order toassist the shaft output of the internal combustion engine 1 with theshaft output of the expander 4, it is necessary to increase a rotationalspeed of the expander 4 by the planetary gear mechanism 122 and thebelt-type continuously variable transmission 123 of the powertransmission system 121 and to match the rotational speed with that ofthe internal combustion engine.

In FIG. 6, as indicated by a solid line, it is assumed that a rotationalspeed of the internal combustion engine 1 increases from 1000 to 5000rpm, and then, the rotational speed decreases to 1000 rpm again.Accordingly, as indicated by a chain line, a rotational speed of theexpander 4 increases from 150 to 2750 rpm, and then, the rotationalspeed decreases to 150 rpm again. And then, a time delay of about 0.5 soccurs between the rising of the rotational speed of the internalcombustion engine 1 and the rising of the rotational speed of theexpander 4, and a time delay of about 0.5 s occurs between the fallingof the rotational speed of the internal combustion engine 1 and thefalling of the rotational speed of the expander 4.

A broken line of FIG. 6 indicates a change gear ratio of the belt-typecontinuously variable transmission 123 required for matching arotational speed of the internal combustion engine 1 and a rotationalspeed of the expansion machine 4. When a rotational speed of theinternal combustion engine 1 rises, a rotational speed of the expander 4does not quickly rise due to a time delay. Thus, a change gear ratio ofthe belt-type continuously variable transmission 123 reaches 50 in amoment. Further, when the rotational speed of the internal combustionengine 1 falls as well, the gear change ratio of the belt-typecontinuously variable transmission reaches 10 in a moment because of theabove time delay.

However, when a rotational speed of the internal combustion engine 1 isstable, a change gear ratio required for matching a rotational speed ofthe internal combustion engine 1 and a rotational speed of the expander4 is within a range of available gear change ratios (e.g., 0.5 to 2.5)of the belt-type continuously variable transmission 123. The availablegear change ratios are indicated by a diagonally shaded area. Therefore,except for rapid acceleration and rapid deceleration of the internalcombustion engine 1, it is possible to match a rotational speed of theinternal combustion engine 1 and a rotational speed of the expander 4 bycontrolling a change gear ratio of the belt-type continuously variabletransmission 123.

Additionally, a change gear ratio computed by a rotational speed of theinternal combustion engine 1 (indicated by a solid line) and arotational speed of the expander 4 (indicated by a chain line) does notconform to the change gear ratio indicated by the broken line. This isbecause a change gear ratio of the overall power transmission system 121is not only determined by a change gear ratio of the belt-typecontinuously variable transmission 123 but also changed by a change gearratio of the planetary gear mechanism 122.

In this way, when the above described matching cannot be made bycontrolling a change gear ratio of the belt-type continuously variabletransmission 123 due to delay in response of a rotational speed of theexpander 4, the torque limiter 146 placed on the output shaft 129 of theexpander 4 is slipped or the clutch 148 placed on the output shaft 137of the belt-type continuously variable transmission 13 is disengaged soas to prevent overload from being applied on the expander 4.

Next, referring to FIGS. 7 to 12, the control of the planetary gearmechanism 122 will be discussed below. In these drawings, referencecharacter S denotes a rotational speed of the sun gear 125 of theplanetary gear mechanism 122 (that is, a rotational speed of theinput/output shaft 131 of the power generator/motor 124), referencecharacter C denotes a rotational speed of the planetary carrier 127(that is, a rotational speed of the output shaft 129 of the expander 4),and reference character R denotes a rotational speed of the ring gear126 (that is, a rotational speed of the input shaft 135 of the belt-typecontinuously variable transmission 123).

FIG. 7 shows a startup of the internal combustion engine 1. The powergenerator/motor 124 is caused to function as a motor to drive the sungear 125 of the planetary gear mechanism 122 in a state in which thecarrier brake 130 is engaged to restrain the rotation of the outputshaft 129 of the expander 4. At this point, since the planetary carrier127 is restrained by the carrier brake 130, the ring gear 126 is rotatedto drive the input shaft 135 of the belt-type continuously variabletransmission 123, and the output axis 142 of the internal combustionengine 1 is driven. The output shaft 142 is connected to the outputshaft 137 of the belt-type continuously variable transmission 123. As aresult, the internal combustion engine 1 is cranked and started by theoutput shaft 142. In this way, it is possible to eliminate the necessityfor a special cell motor by using the power generator/motor 124 as acell motor for starting the internal combustion engine 1.

FIG. 8 shows a state in which the evaporator 3 does not generate vaporand the expander 4 is not operated after the startup of the internalcombustion engine 1. The clutch 148 of the output shaft 137 of thebelt-type continuously variable transmission 123 is disengaged, so thata vehicle can be traveled by the shaft output of the internal combustionengine 1. Further, when the vehicle is not traveled, the clutch 148 ismaintained in an engaging state, so that the shaft output of theinternal combustion engine 1 is transmitted to the power generator/motor124 via the belt-type continuously variable transmission 123, and thepower generator/motor 124 is caused to function as a power generator soas to charge the battery 134.

Besides, a non-operating state of the expander 4 is not limited to thestartup but also includes a shift from an operating state to asuspending state.

FIG. 9 shows a state in which a predetermined time passes after thestartup of the internal combustion engine 1, and the evaporator 3 cangenerate vapor. In order to smoothly start the expander 4, the outputshaft 129 thereof needs to be driven from the outside. For such driving,regardless of whether a vehicle is traveled or not, the sun gear brake132 is engaged to restrain the rotation of the input/output shaft 131 ofthe power generator/motor 124, and the clutch 148 of the output shaft137 of the belt-type continuously variable transmission 123 is engaged.Thus, the shaft output of the internal combustion engine 1 is inverselytransmitted to the expander 4 via the belt-type continuously variabletransmission 123 and the planetary gear mechanism 122, thereby smoothlystarting the expander 4. Additionally, instead of starting the expander4 with shaft output of the internal combustion engine 1, the followingoperation is also applicable: the clutch 148 of the output shaft 137 ofthe belt-type continuously variable transmission 123 is disengaged andthe ring gear brake 133 is engaged to restrain the rotation of the inputshaft 135 of the belt-type continuously variable transmission 123, andin this state, the power generator/motor 124 is caused to function as amotor and rotate the expander 4 so as to start the expander 4.

As described above, in the case where the expander 4 is cranked andstarted by causing the power generator/motor 124 to function as a motor,even when the expander 4 is in a state before warming up and condensategenerated by condensing vapor builds up in the expander 4, thecondensate can be discharged to the outside of the expander 4 bycranking.

FIG. 14 shows the case where the power generator/motor 124 is caused tofunction as a motor to crank the expander 4. In this case, the expander4 can be started by rotating the power generator/motor 124 in a state inwhich the output shaft 137 of the belt-type continuously variabletransmission 123 is fixed. Even when condensate builds up in theexpander 4 at a low temperature, the condensate is discharged to theoutside of the expander 4 by cranking. Hence, it is possible to preventthe expander 4 from being rotated in an opposite direction upon startup.

FIG. 10 shows the case where the shaft output of the internal combustionengine 1 is assisted by the shaft output of the expander 4 insteady-state traveling of the vehicle. In this case, like FIG. 9, thesun gear brake 132 is engaged to restrain the rotation of theinput/output shaft 131 of the power generator/motor 124, and the clutch148 on the output shaft 137 of the belt-type continuously variabletransmission 123 is engaged. Thus, the output shaft 129 of the expander4 is connected to the output shaft 142 of the internal combustion engine1 via the planetary gear mechanism 122 and the belt-type continuouslyvariable transmission 123, and a change gear ratio of the belt-typecontinuously variable transmission 123 is controlled to match arotational speed, which is transmitted to the output shaft 142 of theinternal combustion engine 1 from the expander 4, with a rotationalspeed of the internal combustion engine 1, so that the shaft output ofthe internal combustion engine 1 can be assisted by the shaft output ofthe expander 4.

FIGS. 11 and 12 show the case where a rotational speed of the internalcombustion engine 1 rapidly increases or decreases and a rotationalspeed of the expander 4 cannot change accordingly. In this case, theclutch 148 on the output shaft 137 of the belt-type continuouslyvariable transmission 123 is disengaged to prevent overload beingapplied to the expander 4, and the ring gear brake 133 is engaged torestrain the rotation of the ring gear 126. Hence, the powergenerator/motor 124 is driven by the shaft output of the expander 4 andis caused to function as a motor, so that the battery 134 can be chargedby generated electricity.

FIG. 13 shows the case where a rotational speed of the internalcombustion engine 1 rapidly increases upon climbing and so on, arotational speed of the expander 4 cannot increase accordingly, and theshaft output of the internal combustion engine 1 needs to be assisted bythe shaft output of the expander 4. In this case, in a state in whichthe carrier brake 130, the sun gear brake 132, and the ring gear brake133 are all disengaged, the power generator/motor 124 is caused tofunction as a motor. Thus, the shaft output of the power generator/motor124 is transmitted to the side of the belt-type continuously variabletransmission 123 so as to assist the shaft output of the internalcombustion engine 1.

As described above, the power transmission system 121 including theplanetary gear mechanism 122 and the belt-type continuously variabletransmission 123 is placed between the output shaft 129 of the expander4 and the output shaft 137 of the internal combustion engine 1. Thus, itis possible to absorb a delay in response of a rotational speed of theexpander 4 relative to a rotational speed of the internal combustionengine 1 and a difference between a rotational speed range of theinternal combustion engine 1 and a rotational speed range of theexpander 4, thereby effectively combining the shaft output of theexpander 4 with the shaft output of the internal combustion engine 1.Namely, a change gear ratio of the belt-type continuously variabletransmission 123 is controlled according to the output characteristicsof the expander 4 within a range of the output characteristics, so thatthe expander 4 can be efficiently operated to effectively utilizethermal energy of exhaust gas. Further, the carrier brake 130, the sungear brake 132, and the ring gear brake 133 of the planetary gearmechanism 122 are selectively engaged, so that transmission of drivingforce among three of the expander 4, the power generator/motor 124, andthe internal combustion engine 1 can be changed in various mannersaccording to an operating condition of a vehicle, and thermal energy ofexhaust gas can be effectively used so as to contribute to improvementin performance of the vehicle.

Next, referring to FIGS. 15 to 24, the structure of the expander 4 willbe discussed below.

In FIGS. 15 to 18, a casing 7 is formed by metallic first and secondhalf bodies 8 and 9. The half bodies 8 and 9 are each formed by a mainbody 11, which has a concave part 10 being substantially oval, and acircular flange 12, which is integrated with the main body 11. Thecircular flanges 12 are superposed one on another via a metallic gasket13 so as to form a rotor chamber 14, which is substantially oval.Further, an external surface of the main body 11 of the first half body8 is covered with a main body 16 of a shell-shaped member 15 that isshaped like a deep bowl. A circular flange 17 integrated with the mainbody 16 is overlaid on the circular flange 12 of the first half body 8via a gasket 18. The three circular flanges 12, 12, and 17 are engagedby a bolt 19 at a plurality of places in a circumferential direction.Thus, a relay chamber 20 is formed between the main bodies 11 and 16 ofthe shell-shaped member 15 and the first half body 8.

The main bodies 11 of the half bodies 8 and 9 have hollow bearingcylinders 21 and 22, which protrude outward, on the external surfaces. Alarge-diameter portion 24 of a hollow output shaft 23, which penetratesthe rotor chamber 14, is rotatably supported on the hollow bearingcylinders 21 and 22 via a bearing metal (or bearing made of resin) 25.Hence, an axis line L of the output shaft 23 passes through anintersection point of a major axis and a minor axis in the rotor chamber14, which is substantially oval. Moreover, a small-diameter portion 26of the output shaft 23 protrudes outward from a hole 27, which exists onthe hollow bearing cylinder 22 of the second half body 9, and thesmall-diameter portion 26 is connected to a transmission shaft 28 via aspline connection 29. Portions between the small-diameter portion 26 andthe hole 27 are sealed with two seal rings 30.

A circular rotor 31 is stored in the rotor chamber 14, and a shaftmounting hole 32 at the center of the rotor 31 and the large-diameterportion 24 of the output shaft 23 are engaged with each other, and anengaging connection 33 is provided between the rotor 31 and thelarge-diameter portion 24. Thus, a rotation axis line of the rotor 31conforms to the axis line L of the output shaft 23, so that “L” is usedin common as a reference character of the rotation axis line.

A plurality of slot-shaped spaces 34 radially extend from the shaftmounting hole 32 with the rotation axis line L of the rotor 31 servingas the center. In the present embodiment, the twelve slot-shaped spaces34 are formed on the circumference at equal intervals. The spaces 34 aresubstantially U-shaped in a virtual plane, which intersect end faces 35,such that the spaces 34 are opened sequentially on the end faces 35 andan outer peripheral surface 36 of the rotor 31 with a narrow width in acircumferential direction.

In the slot-shaped spaces 34, first to twelfth vane piston units U1 toU12 having identical structures are mounted so as to freely reciprocatein a radial direction as follows: in the substantially U-shaped spaces34, stepped holes 38 are formed on parts 37 for dividing the innerperiphery of the space 34, and stepped cylinder members 39 made ofceramic (or carbon) are fitted into the stepped holes 38. An end face ofa small-diameter portion a of the cylinder member 39 is in contact withthe outer peripheral surface of the large-diameter portion 24 of theoutput shaft 23, and a small-diameter portion hole b is connected to athrough-hole c, which is opened on the outer peripheral surface of thelarge-diameter portion 24. Further, a guide cylinder 40 is placed on theoutside of the cylinder member 39 so as to be positioned coaxially withthe member 39. The outer end of the guide cylinder 40 is locked to anopening of the space 34, which exists on the outer peripheral surface ofthe rotor 31, and the inner end is fitted into a large-diameter portionhole d of the stepped hole 38 and is in contact with the cylinder member39. Further, the guide cylinder 40 has a pair of long grooves e whichextend so as to be opposed to each other from the outer end to theproximity of the inner end of the guide cylinder 40, and the longgrooves e face the spaces 34. Pistons 41 made of ceramic are slidablyfitted into large-diameter portion cylinder holes f of the cylindermembers 39. The leading ends of the pistons 41 are always placed in theguide cylinders 40.

As shown in FIGS. 15 and 19, in a virtual plane A including the rotationaxis line L of the rotor 31, a section B of the rotor chamber 14 iscomprised of a pair of half-round sections B1 having diameters g opposedto each other, and a rectangular section B2 formed by connectingopposing ends and the other opposing ends of the diameters g of thehalf-round sections B1, so that the section B is substantially shapedlike a field track shape. In FIG. 19, a solid line indicates the largestsection including a major axis while a part indicated partially by achain double-dashed line shows the smallest section including a minoraxis. As indicated by a dotted line in FIG. 19, the rotor 31 has asection D which is somewhat smaller than the smallest section includinga minor axis of the rotor chamber 14.

As shown in FIGS. 15 and 20 to 23, a vane 42 is formed by a vane body 43which is in the form of a substantially U-shaped plate (horseshoe), aseal member 44 which is mounted on the vane body 43 and is in the formof a substantially U-shaped plate, and a vane spring 58.

The vane body 43 has a semi-arcuate portion 46, which corresponds to aninner peripheral surface 45 formed by the half-round section B1 of therotor chamber 14, and a pair of parallel portions 48 that correspond toopposing inner end faces 47 formed by the rectangular section B2. On theend sides of the parallel portions 48, a rectangualr U-shaped notch 49is provided, rectangular blind holes 50 are opened on the bottom of thenotch 49, and a minor shaft 51 is provided which is closer to the endsides than the notch 49 and protrude to the outside. Further, U-shapedgrooves 52 opened outward are sequentially formed on the outerperipheral portion of the semi-arcuate portion 46 and the parallelportions 48, and both ends of the U-shaped groove 52 are respectivelyconnected to the notch 49. Moreover, a pair of protrusions 53 havingsegmental sections is provided on both planes of the semi-arcuateportion 46. The protrusions 53 are disposed such that the axis line L1of a virtual circular cylinder comprised of the protrusions 53 conformsto a straight line which divides an interval between the parallelportions 48 into two equal parts and divides the semi-arcuate portion 46into equal two parts in a circumferential direction. Besides, the innerends of the protrusions 53 slightly protrude to a space between theparallel portions 48.

The seal member 44 is comprised of, for example, PTFE. The seal member44 has a half segment 55, which slides the inner peripheral surface 45formed by the half-round section B1 of the rotor chamber 14, and a pairof parallel portions 56, which slide opposing inner end faces 47 formedby the rectangular section B2. Also, a pair of elastic claws 57 areprovided so as to be warped inward on the inner peripheral surface ofthe half segment 55.

The seal member 44 is mounted on the U-shaped groove 52 of the vane body43, and a vane spring 58 is fitted into the blind hole 50. Additionally,a roller 59 having a ball bearing structure is mounted on the minor axis51. The vanes 42 are slidably accommodated in the slot-shaped spaces 34of the rotor 31. At this point, the protrusions 53 of the vane body 43are positioned in the guide cylinder 40, and opposite sides of theprotrusion 53 are respectively positioned in the long grooves e of theguide cylinder 40. Hence, the inner end faces of the protrusions 53 canbe in contact with the outer end face of the piston 41. The rollers 59are respectively engaged rotatably to annular grooves 60. The annulargrooves 60 are substantially oval and are formed on the opposing innerend faces 47 of the first and second half bodies 8 and 9. A distancebetween the annular groove 60 and the rotor chamber 14 is constant overthe circumference. Further, progressive motions of the pistons 41 areconverted to rotational motion of the rotor 31 via the vanes 42 by usingengagement between the rollers 59 and the annular grooves 60.

As shown in FIG. 18, due to a cooperation between the roller 59 and theannular grooves 60, a semi-arcuate end face 61 on the semi-arcuateportion 46 of the vane body 43 is always away from the inner peripheralsurface 45 of the rotor chamber 14, and both of the parallel portions 48are always away from the opposed inner end faces 47 of the rotor chamber14, thereby reducing friction loss. And then, since an track isregulated by the annular groove 60 formed by a pair of protrusions, thevane 42 has rotation with a small displacement-type angle in a shaftdirection via the roller 59 due to a lateral track error, therebyincreasing contact pressure with the inner peripheral surface 45 of therotor chamber 14. At this point, the vane body 43 in the form of asubstantially U-shaped plate (horseshoe) is shorter in length in adiameter direction of a contact part with the casing 7 as compared witha square (rectangular) vane, thereby largely reducing the displacementvolume. Moreover, as is apparently shown in FIG. 15, in the seal member44, both of the parallel portions 56 are in intimate contact with theopposed inner end faces 47 of the rotor chamber 14 due to elastic forceof each vane spring 58, and a sealing effect is carried out on theannular grooves 60 via the ends of the parallel portions 56 and thevanes 42. Besides, the semi-arcuate portion 55 is brought into closecontact with the inner peripheral surface 45 by pressing both of theelastic claws 57 between the vane body 43 and the inner peripheralsurface 45 in the rotor chamber 14. Namely, the vane 42 in the form of asubstantially U-shaped plate does not have an inflection point incontrast to a square (rectangular) vane, resulting in good contact. Asquare vane has corners and the sealing property is hard to maintain.Thus, the sealing property is improved between the vanes 42 and therotor chamber 14. Moreover, as thermal expansion proceeds, the vanes 42and the rotor chamber 14 are deformed. At this point, in contrast to asquare vane, the substantially U-shaped vane 42 is deformed more evenlywith a similar Fig., resulting in few irregular clearances between thevanes 42 and the rotor chamber 14, and the sealing property can bemaintained well.

In FIGS. 15 and 16, the large-diameter portion 24 of the output axis 23has a thick portion 62, which is supported by the bearing metal 25 ofthe second half body 9, and a thin portion 63, which extends from thethick portion 62 and is supported by the bearing metal 25 of the firsthalf body 8. A hollow shaft 64 made of ceramic (or metal) is fitted intothe thin portion 63 so as to rotate integrally with the output shaft 23.A fixed shaft 65 is placed inside the hollow shaft 64. The fixed shaft65 is formed by a large-diameter solid portion 66, which is fitted intothe hollow shaft 64 so as to be within a thickness of the rotor 31 in anaxial direction, a small-diameter solid portion 69, which is fitted intoholes 67 via two sealing rings 68, the holes 67 being placed on thethick portion 62 of the output shaft 23, and a thin hollow portion 70,which extends from the large-diameter solid portion 66 and is fittedinto the hollow shaft 64. A seal ring 71 is provided between the endouter peripheral surface of the hollow portion 70 and the innerperipheral surface of the hollow bearing cylinder 21 of the first halfbody 8. In the main body 16 of the shell-shaped member 15, an end wall73 of a hollow cylinder 72 is attached on the inner surface of thecentral part of the main body 16 via the seal ring 74. The hollowcylinder 72 is placed coaxially with the output shaft 23. The inner endof a short outer cylinder 75, which extends inward from the outercircumference of the end wall 73, is connected to the hollow bearingcylinder 21 of the first half body 8 via a connecting cylinder 76. Aninner tube 77 is placed on the end wall 73 so as to penetrate the endwall 73 with a small diameter and a long length. The inner end of theinner tube 77 is fitted into a stepped hole h, which is placed on thelarge-diameter portion solid part 66 of the fixed shaft 65, togetherwith a short hollow connecting tube 78 protruding from the inner end ofthe inner tube 77. The outer end of the inner tube 77 protrudes outwardfrom a hole 79 of the shell-shaped member 15, and the inner end of afirst high-temperature high-pressure vapor introduction tube 80, whichis inserted into the inner tube 77 from the outer end of the inner tube77, is fitted into the hollow connecting tube 78. A cap member 81 isscrewed into the outer end of the inner tube 77. A flange 83 of theholder cylinder 82, which holds the introduction tube 80, is crimped bythe cap member 81 onto the outer end face of the inner tube 77 via theseal ring 84.

As shown in FIGS. 15 to 17 and 24, a rotating valve V is provided on thelarge-diameter portion solid part 66 of the fixed shaft 65 and on thecylinder member 39 of first to twelfth vane piston units U1 to U12. Therotating valve V supplies high-temperature high-pressure vapor via aplurality of through-holes c sequentially formed on the hollow shaft 64and the output shaft 23, for example, twelve through-holes c in thepresent embodiment, and the rotating valve V discharges firstdropped-temperature/pressure vapor after expansion from the cylindermembers 39 via the through-holes c. The rotating valve V is formed asfollows:

FIG. 24 shows the structure of the rotating valve V which supplies anddischarges vapor to the cylinder members 39 of the expander 4 at apredetermined timing. In the large-diameter portion solid part 66, firstand second holes 86 and 87 are formed so as to extend in oppositedirections from a space 85 connected to the hollow connecting tube 78,and the first and second holes 86 and 87 are opened on the bottoms offirst and second concave parts 88 and 89, which are opened on the outerperipheral surface of the large-diameter portion solid part 66. Firstand second sealing blocks 92 and 93, which are made of carbon and havefeed openings 90 and 91, are mounted on the first and second concaveparts 88 and 89. The outer peripheral surfaces of the sealing blocks 92and 93 slide on the inner peripheral surface of the hollow shaft 64. Inthe first and second holes 86 and 87, short first and second feed tubes94 and 95, which are coaxially disposed, are loosely inserted. Taperedouter peripheral surfaces i and j of first and second seal cylinders 96and 97, which are fitted into the end-side outer peripheral surfaces ofthe first and second feed tubes 94 and 95, are disposed inside the feedopenings 90 and 91 of the first and second sealing block 92 and 93, andthe tapered outer peripheral surfaces i and j are fitted into the innerperipheral surfaces of tapered holes k and m, which are connected to thetapered outer peripheral surfaces i and j. Moreover, in thelarge-diameter solid portion 66, first and second annular concaveportions n and o are formed for surrounding the first and second feedtubes 94 and 95, and first and second blind hole concave portions p andq being adjacent to the annular concave portions are formed so as toface the first and second sealing blocks 92 and 93. First and secondbellows-shaped elastic bodies 98 and 99, each having one end fitted intothe outer peripheral surfaces of the first and second seal cylinders 96and 97, are stored in the first and second ring-shaped concave parts nand o. Further, first and second coil springs 100 and 101 are storedrespectively in the first and second blind hole concave parts p and q.The first and second sealing blocks 92 and 93 are pressed onto the innerperipheral surface of the hollow shaft 64 by elastic force of the firstand second bellows-like elastic bodies 98 and 99 and the first andsecond coil springs 100 and 101.

Besides, in the large-diameter portion solid part 66, between the firstcoil spring 100 and the second bellows-like elastic body 99 and betweenthe second coil spring 101 and the first bellows-like elastic body 98,first and second concave discharging parts 102 and 103 are formed whichare always connected to the two through-holes c, and first and seconddischarging holes 104 and 105 are formed which extend in parallel withthe introduction tube 80 from the discharging parts 102 and 103 and areopened in a hollow part r of the fixed shaft 65.

Like the first sealing block 92 and the second sealing block 93, whenthe same kind of members are indicated by “first” and “second”, themembers are point symmetric with each other with respect to the axisline of the fixed shaft 65.

In the hollow part r of the fixed axis 65 and in the outer cylinder 75of the hollow cylinder 72, a passage s for the first low-temperaturelow-pressure vapor is provided. The passage s is connected to the relaychamber 20 via a plurality of through-holes t penetrating acircumferential wall of the outer cylinder 75.

As described above, the rotating valve V is placed at the center of theexpander 4, and high-temperature high-pressure vapor, which is suppliedthrough the inside of the fixed shaft 65 placed at the center of therotating valve V, is distributed to the cylinder members 39 according tothe rotation of the rotor 31. Hence, it is possible to eliminate thenecessity for a supply and exhaust valve used in an ordinary pistonmechanism, thereby simplifying the configuration. Further, on therotating valve V, the fixed axis 65 and the hollow axis 64 slide on eachother on the small-diameter portion part having a low peripheral speed,resulting in compatibility between sealing property and wear resistance.

As shown in FIGS. 15 and 18, on the outer circumference of the main body11 of the first half body 8, first and second introduction hole groups107 and 108, which are each comprised of a plurality of introductionholes 106 arranged in a radius direction, are formed near both ends of aminor axis of the rotor chamber 14. The first low-temperaturelow-pressure vapor in the relay chamber 20 is introduced into the rotorchamber 14 via the introduction hole groups 107 and 108. Further, on thecircumference of the main body 11 of the second half body 9, a firstintroduction hole group 110, which are comprised of a plurality ofintroduction holes 109 arranged in a radius direction and in acircumferential direction, is formed between an end of a major axis andthe second introduction hole group 108. Moreover, a second introductionhole group 111, which are comprised of the plurality of introductionholes 109 arranged in a radius direction and in a circumferentialdirection, is formed between the other end of the major axis and thefirst introduction hole group 109. From the first and secondintroduction hole groups 110 and 111, due to expansion between theadjacent vanes 42, second low-temperature low-pressure vapor with lowertemperature and pressure is discharged to the outside.

The output shaft 23 and so on are lubricated with water. A lubricatingchannel has the following configuration. Namely, as shown in FIGS. 15and 16, a feed pipe 113 is connected to a feed hole 112, which is formedon the hollow bearing cylinder 22 of the second half body 9. The feedhole 112 is connected to a housing 114, where the bearing metal 25 onthe second half body 9 faces, the housing 114 is connected to a waterpassage hole u formed on the thick portion 62 of the output shaft 23,the water passage hole u is connected to a plurality of water passagegrooves v (see FIG. 24) extending in a direction of a bus on the outerperipheral surface of the hollow shaft 64, and the water passage groovesv are each connected to a housing 115 where the bearing metal 25 on thesecond half body 8 faces. Moreover, on the inner end face of the thickportion 62 of the output shaft 23, a ring-shaped concave part w isprovided, which connects the water passage hole u and a sliding partbetween the hollow shaft 64 and the large-diameter portion solid part 66of the fixed shaft 65.

Hence, lubrication is made with water between the bearing metals 25 andthe output shaft 23 and between the hollow shaft 64 and the fixed shaft65, and lubrication is made between the casing 7, the seal member 44,and the rollers 59 with water which enters the rotor chamber 14 from agap between both of the bearing metals 25 and the output shaft 23.

In FIG. 17, the same operation is performed by the first and seventhvane piston units U1 and U7, which are point symmetric with respect tothe rotation axis line L of the rotor 31. The same operation is alsoperformed by the second and eighth vane piston units U2 and U8 and soon, which are point symmetric with each other.

For example, referring to FIG. 24, it is assumed that an axis line of afirst feed tube 94 is slightly shifted counterclockwise from a minoraxis position E of the rotor chamber 14 in FIG. 17, the first vanepiston unit U1 is placed on the minor axis position E, high-temperaturehigh-pressure vapor is not supplied to a large-diameter portion cylinderhole f, so that the pistons 41 and the vanes 42 are positioned onretreating positions.

In this state, when the rotor 31 is slightly rotated counterclockwise inFIG. 17, the feed opening 90 of the first sealing block 92 and thethrough-hole c are connected to each other, and high-temperaturehigh-pressure vapor from the introduction tube 80 is introduced to thelarge-diameter portion cylinder hole f through the small diameter holeb. Thus, the pistons 41 are moved forward. Since the vane 42 slides to amajor axis position F of the rotor chamber 14, the forward motion isconverted to rotational motion via the vane 42 by engagement of the ringgroove 60 and the roller 59, which is integrated with the vane 42. Whenthe through-hole c is shifted from the feed opening 90, high-temperaturehigh-pressure vapor is expanded in the large-diameter portion cylinderhole f and further moves forward the pistons 41. Thus, the rotation ofthe rotor 31 continues. The expansion of high-temperature high-pressurevapor is completed when first vane piston unit U1 reaches the major axisposition F of the rotor chamber 14. Thereafter, the pistons 41 arecaused to retreat by the vanes 42, so that the first low-temperaturelow-pressure vapor in the large cylinder hole f is discharged to therelay chamber 20 via the small-diameter portion hole b, the through-holec, the first concave discharging part 102, the first discharging hole104, the passages (see FIG. 16), and the through-hole t, according tothe rotation of the rotor 31. Subsequently, as shown in FIGS. 15 and 18,the vapor is introduced to the rotor chamber 14 via the firstintroduction hole group 107, the vapor is further expanded between theadjacent vanes 42 to rotate the rotor 31, and then, the secondlow-temperature low-pressure vapor is discharged to the outside from thefirst introduction hole group 110.

In this way, the pistons 41 are operated by expansion ofhigh-temperature high-pressure vapor, the rotor 31 is rotated via thevanes 42, or the rotor 31 is rotated via the vanes 42 by expansion oflow-temperature low-pressure vapor, which is generated by reducing apressure of the high-temperature high-pressure vapor, so as to obtainoutput from the output shaft 23.

Besides, in addition to Examples, as a configuration for convertingforward motion of the pistons 41 to rotational motion of the rotor 31,forward motion of the pistons 41 may be directly transmitted to therollers 59 without passing through the vanes 42 and may be converted torotational motion by engagement with the ring grooves 60. Moreover, dueto cooperation of the rollers 59 and the ring grooves 60, as describedabove, the vanes 42 only need to be separated from the inner peripheralsurface 45 and the opposing inner end faces 47 of the rotor chamber 14all the time substantially at a fixed interval. The pistons 41 and therollers 59, and the vanes 42 and the rollers 59 may mainly cooperatewith the ring groove 60.

When the expander 4 is used as a compressor, the rotor 31 is rotatedclockwise by the output shaft 23 in FIG. 17, outside air as fluid isabsorbed by the vanes 42 into the rotor chamber 14 from the first andsecond introduction hole groups 110 and 111, low-compressed air obtainedthus is supplied to the large-diameter portion cylinder hole f from thefirst and second introduction hole groups 107 and 108 via the relaychamber 20, the through-holes t, the passage s, the first and seconddischarging holes 104 and 105, the first and second concave dischargingparts 102 and 103, and the through-hole c. Further, the pistons 41 areoperated to convert low-pressure air to high-pressure air by means ofthe vane 42, and the high-pressure air is introduced to the introductiontube 80 via the through-hole c, the feed openings 90 and 91, and thefirst and second feed tubes 94 and 95.

As is apparent from FIG. 18, a vane-type fluid machine such as a vanepump, a vane motor, a blower, and a vane compressor can be formed by theabove described components. Namely, the vane-type fluid machinecomprises the casing 7 having the rotor chamber 14, the rotor 31 storedin the rotor chamber 14, and the plurality of vanes 42 which areradially disposed around the rotation axis line L and freely reciprocatein a radial direction on the rotor 31. The section B of the rotorchamber 14 on the virtual plane A, which includes the rotation axis lineL of the rotor 31, is comprised of the pair of half-round sections B1having the diameters g opposed to each other, and the rectangularsection B2 formed by connecting opposing ends and the other opposingends of the diameters g. Each of the vanes 42 is comprised of the vanebody 43 and the seal member 44, which is mounted on the vane body 43 andis pressed to the rotor chamber 14 by spring force, centrifugal force,and vapor power. The seal member 44 has the half segment 55 for slidingthe inner peripheral surface 45 formed by the half-round section B1 ofthe rotor chamber 14, and the pair of parallel portions 56 forrespectively sliding the opposing inner end faces 47 formed by therectangular section B2. In this case, each of the vane main bodies 43has a pair of parallel portions 48 corresponding to the parallelportions 56 of the seal member 44, the rollers 59 placed on the parallelportions 48 are rotatably engaged with the ring grooves 60 formed on theopposing inner end faces 47 of the casing 7 such that the end faces ofthe vane main bodies 43 are always separated from the inner peripheralsurface 45 of the rotor chamber 14.

Therefore, the sealing effect between the vane main bodies 43 and theinner peripheral surface of the rotor chamber 14 is generated by springforce of the seal member 44, centrifugal force applied to the sealmember 44, and vapor power which is produced by vapor pressing upwardthe seal member 44. The vapor enters the U-shaped grooves 52 of the vanemain bodies 43 from the rotor chamber 14. In this way, the above sealingeffect is not affected by excessive centrifugal force, which is appliedto the vane main bodies 43 according to the number of revolutions of therotor 31. Thus, a sealing contact pressure does not depend oncentrifugal force applied to the vane main bodies 43, thereby alwaysobtaining compatibility of fine sealing property and low friction.

It should be noted here that Japanese Patent Application Laid-open No.59-41602 discloses a double multi-vane rotating machine. In thismachine, a circular vane supporting ring is placed between an oval outercam ring and an oval inner cam ring, and outer ends and inner ends of aplurality of vanes, which are supported on the vane supporting ring in aradius direction so as to freely slide, are respectively brought intocontact with the inner peripheral surface of the outer cam ring and theouter peripheral surface of the inner cam ring. Therefore, when the vanesupporting ring rotates relative to the outer cam ring and the inner camring, a plurality of operating chambers, which are divided by vanesbetween the outer cam ring and the vane supporting ring, increases anddecreases in capacity so as to act as an expander or compressor, and aplurality of operating chambers, which are divided by vanes between theinner cam ring and the vane supporting ring, increases and decreases incapacity so as to act as an expander or a compressor.

In the above double multi-vane rotating machine, the outer and innerrotating machines can be used as independent expanders, the outer andinner rotating machines can be used as independent compressor, and theouter and inner rotating machines can be respectively used as anexpander and a compressor.

Further, Japanese Patent Application Laid-open No. 60-206990 discloses avane-type rotating machine which can be used as an expander or acompressor. In this machine, between a circular outer cam ring and acircular inner cam ring that are disposed concentrically, a circularintermediate cylinder is eccentrically disposed, the outer ends andinner ends of a plurality of vanes, which are supported by theintermediate cylinder in a radius direction so as to freely slide, arerespectively brought into contact with the inner peripheral surface ofthe outer cam ring and the outer peripheral surface of the inner camring. Therefore, when the intermediate cylinder rotates relative to theouter cam ring and the inner cam ring, a plurality of operatingchambers, which are divided by vanes between the outer cam ring and avane supporting ring, increases and decreases in capacity so as to actas an expander or a compressor, and a plurality of operating chambers,which are divided by vanes between the inner cam ring and the vanesupporting ring, increases and decreases in capacity so as to act as anexpander or a compressor.

In the above vane-type rotating machine, the outer and inner rotatingmachines can be used as independent expanders, and the outer and innerrotating machines can be used as independent compressors. Besides, theouter and inner rotating machines can be connected in series to operateas a two-stage expander or a two-stage compressor by causing workingfluid, which has passed through one of the outer and inner rotatingmachines, to pass through the other rotating machine.

Further, Japanese Patent Application Laid-open No. 57-16293 discloses avane-type rotary compressor. In this compressor, a circular rotor isrotatably disposed in a noncircular cam ring, and in order to shift theends of a plurality of vanes, which are radially supported by the rotor,along the inner peripheral surface of the cam ring, a roller placed atthe midpoint between vanes is guided while being engaged with a rollertrack placed on the casing.

Moreover, Japanese Patent Application Laid-open No. 64-29676 discloses aradial plunger pump. In this pump, a plurality of cylinders are radiallyformed on a rotor which is disposed eccentrically in a circular camring, and the ends of plungers, which are fitted into the cylinders soas to freely slide, are brought into contact with the inner peripheralsurface of the cam ring, and reciprocating motion is carried out, sothat the radial plunger pump is operated as a pump.

Moreover, Japanese Patent Application Laid-open No. 58-48076 discloses aRankine cycle device comprising a vane-type expander. In the device,energy of high-temperature high-pressure vapor, which is generated by anevaporator using a gas burner as a heat source, is converted tomechanical energy via a vane-type expander, and after low-temperaturelow-pressure vapor generated thus is condensed by a condenser, the vaporis returned to the evaporator again via a feed pump.

Incidentally, Japanese Patent Application Laid-open No. 59-41602 andJapanese Patent Application Laid-open No. 60-206990 disclose a pluralityof vane-type rotating machines placed inside and outside in a radiusdirection. The vane-type rotating machine has a simple configuration ofa conversion mechanism for pressure energy and mechanical energy. Whileit is possible to process a large quantity of working fluid with acompact configuration, it is difficult to improve efficiency due to alarge quantity of leakage of working fluid from a sliding part of thevane.

Besides, regarding the radial plunger pump disclosed in Japanese PatentApplication Laid-open No. 64-29676, working fluid has excellent sealingproperty because the working fluid is compressed by the piston which isfitted into the cylinder so as to freely slide, so that even whenhigh-pressure working fluid is used, it is possible to minimize areduction in efficiency that is caused by leakage. Meanwhile, a crankmechanism and a swash plate mechanism are necessary for convertingreciprocating motion to rotational motion, resulting in a complicatedconfiguration.

Therefore, it is desirable that a merit of a piston type and a merit ofa vane type be compatible with each other in the rotating fluid machine.

Hence, in the above described expander 4, first energy conversion meanscomprised of the cylinder members 39 and the pistons 41, and secondenergy conversion means comprised of the vanes 42 are provided in therotor 31, which is used in common. With the cooperation between thefirst and second energy conversion means connected in series, energy ofhigh-temperature high-pressure high vapor can be taken out to the outputshaft 23 as mechanical energy. Therefore, it is possible toautomatically combine mechanical energy output from the first energyconversion means and mechanical energy output from the second energyconversion means via the rotor 31, thereby eliminating the necessity forspecial energy combining means having power transmission means such as agear.

Since the first energy conversion means includes combination of thecylinder 39 and the piston 41 that can seal working fluid with ease andsuppress the occurrence of leakage, it is possible to improve thesealing property of high-temperature high-pressure vapor and to minimizea reduction in efficiency that is caused by leakage. Meanwhile, thesecond energy conversion means is comprised of the vanes 42 which aresupported on the rotor 31 so as to be freely shifted in a radialdirection. Thus, vapor pressure applied to the vanes 42 is directlyconverted to rotational motion of the rotor 31, thereby eliminating thenecessity for a special mechanism for converting reciprocating motion torotational motion, resulting in a simple configuration. Additionally,the second energy conversion means for effectively converting a largequantity of vapor to mechanical energy even at a low pressure isdisposed so as to surround the first energy conversion means. Thus, theexpander 4 can be entirely reduced in size.

The first energy conversion means, which is comprised of the cylinders39 and the pistons 41, achieves high conversion efficiency betweenpressure energy and mechanical energy when high-temperaturehigh-pressure vapor is used as working fluid. Further, the second energyconversion means comprised of the vanes 42 is relatively high inconversion efficiency between pressure energy and mechanical energy evenwhen low-temperature low-pressure vapor is used as working fluid.Therefore, the first and second energy conversion means are connected,in series, high-temperature high-pressure vapor is firstly caused topass through the first energy conversion means and is converted tomechanical energy, so that first low-temperature low-pressure vapor witha lower pressure is caused to pass through the second energy conversionmeans and is converted to mechanical energy again. Hence, energyincluded in the original high-temperature high-pressure vapor can befully converted to mechanical energy in an effective manner.

Additionally, even when the expander 4 of the present embodiment is usedas a compressor, the rotor 31 is rotated by mechanical energy from theoutside, air inhaled into the rotor chamber 14 is compressed andincreased in temperature by the second energy conversion means, which iseffectively operated even by relatively low-temperature low-pressureworking fluid, and the compressed air with an increased temperature isfurther compressed and increased in temperature by the first energyconversion means, which is effectively operated by relativelyhigh-temperature high-pressure working fluid. Hence, mechanical energycan be efficiently converted to pressure energy (thermal energy) ofcompressed air. Thus, with combination of the first energy conversionmeans comprised of the cylinder 39 and the piston 41, and the secondenergy conversion means comprised of the vanes 42, it is possible toobtain a high-performance rotating fluid machine which combines thecharacteristics of the first and second energy conversion means.

Further, the rotation axis line L of the rotor 31 (that is, the rotationaxis L of the output shaft 23) conforms to the center of the rotorchamber 14, and when the rotor 31 is divided into four by 90°longitudinally and laterally in FIGS. 17 and 18, pressure energy isconverted to mechanical energy in the upper right quadrant and the lowerleft quadrant, which are point symmetric with respect to the rotationaxis line L. Thus, it is possible to prevent unbalanced load from beingapplied to the rotor 31, thereby suppressing the occurrence ofvibration. Namely, a part for converting pressure energy of workingfluid to mechanical energy and a part for converting mechanical energyto pressure energy of working fluid are positioned on two places shiftedby 180° around the rotation axis line L serving as the center. Thus,load applied to the rotor 31 is used as couple and achieves smoothrotation, and suction timing and discharging timing can be moreefficient.

Namely, the rotating fluid machine comprises at least the first energyconversion means and the second energy conversion means, inputs workingfluid having pressure energy to the first and second energy conversionmeans to convert the pressure energy to mechanical energy, so that therotating machine can function as an expander for combining mechanicalenergy generated by the first and second energy conversion means andoutputting the mechanical energy, and besides, the rotating machineinputs mechanical energy to the first and second energy conversion meansto convert the mechanical energy to pressure energy of working fluid, sothat the rotating machine can function as a compressor for combiningpressure energy of working fluid that is generated by the first andsecond energy conversion means and outputting the pressure energy. Inthe above rotating fluid machine, the first energy conversion means isformed by the cylinders which are formed radially on the rotor rotatablystored in the rotor chamber, and the pistons which slide in thecylinders. The second energy conversion means is formed by the vaneswhich are placed in a radial direction from the rotor and have the outerperipheral surfaces sliding on the inner peripheral surface of the rotorchamber.

According to the first arrangement, the first energy conversion means isformed by the cylinders which are formed radially on the rotor rotatablystored in the rotor chamber, and the pistons which slide in thecylinders. Thus, it is possible to improve the sealing property ofhigh-pressure working fluid and to minimize a reduction in efficiencythat is caused by leakage. Moreover, the second energy conversion meansis formed by the vanes which are movably supported on the rotor in aradial direction and slide on the inner peripheral surface of the rotorchamber. Hence, the conversion mechanism for pressure energy andmechanical energy can be simplified, and a large amount of working fluidcan be processed with a compact configuration. In this way, withcombination of the first energy conversion means having the pistons andcylinders and the second energy conversion means having the vanes, it ispossible to obtain a high-performance rotating fluid machine which hasthe characteristics of the first and second energy conversion means.

In addition to the first arrangement, the first energy conversion meansalternately converts reciprocating motion of the piston and rotationalmotion of the rotation shaft, and the second energy conversion meansalternately converts the shift of the vanes in a circumferentialdirection and the rotational motion of the rotation shaft.

According to the second arrangement, the first energy conversion meansalternately converts reciprocating motion of the piston and therotational motion of the rotation shaft, and the second energyconversion means alternately converts a shift of the vane in acircumferential direction and the rotational motion of the rotationshaft. Hence, fluid is compressed by the first and second energyconversion means by inputting external force from the rotation shaft,and the rotation shaft can be driven by the first and second energyconversion means by supplying high-pressure fluid. Hence, mechanicalenergy can be combined and output by the first and second energyconversion means, or pressure energy of working fluid can be combinedand output by the first and second energy conversion means.

In addition to the second arrangement, the rotation shaft supports therotor.

According to the third arrangement, since the rotor is supported by therotation shaft, mechanical energy generated by the pistons placed on therotor, the cylinders, or the vanes can be efficiently output to therotation shaft, and only by inputting mechanical energy to the rotationshaft, working fluid can be efficiently compressed by the pistons, whichare placed on the rotor supported on the rotation shaft, the cylinders,or the vanes.

Further, in addition to the first arrangement, in the case of thefunction as an expander, a total quantity of working fluid passingthrough the first energy conversion means passes through the secondenergy conversion means, and in the case of the function as acompressor, a total quantity of working fluid passing through the secondenergy conversion means passes through the first energy conversionmeans.

According to the fourth arrangement, the first and second energyconversion means are connected in series, in the case of the function asan expander, high-pressure working fluid is initially caused to passthrough the first energy conversion means to partially convert pressureenergy to mechanical energy, and working fluid reduced in pressure isfurther caused to pass through the second energy conversion means toconvert the remaining pressure energy to mechanical energy. Thus,pressure energy of the working fluid can be efficiently converted tomechanical energy. Conversely, in the case of the function as acompressor, the rotation shaft is rotated by the mechanical energy,working fluid is compressed by the second energy conversion means, andthe compressed working fluid is further compressed by the first energyconversion means, so that mechanical energy can be efficiently convertedto pressure energy of working fluid.

Moreover, in addition to the first arrangement, in the case of thefunction as an expander, pressure energy of working fluid is convertedto mechanical energy at two places where the rotor is shifted in phaseby 180°. In the case of the function as a compressor, mechanical energyis converted to pressure energy of working fluid at two places where therotor is shifted in phase by 180°.

According to the fifth arrangement, a part for converting pressureenergy of working fluid to mechanical energy or a part for convertingmechanical energy to pressure energy of working fluid is disposed at twoplaces where the rotor is shifted in phase by 180°. Hence, load appliedto the rotor serves as couple so as to achieve smooth rotation of therotor, and it is possible to improve efficiency of suction timing anddischarging timing.

Further, Japanese Patent Application Laid-open No. 59-41602 and JapanesePatent Application Laid-open No. 60-206990 disclose that the vanes arepressed by pressure of high-pressure fluid in a circumferentialdirection to rotate the rotor, or the rotor is rotated by external forceand fluid is compressed by the vanes. When the pistons are provided inaddition to the vanes, the pistons being fitted into the cylinders so asto freely slide, the cylinders being placed radially on the rotor, andconversion is made between mechanical energy and pressure energy ofworking fluid by using the pistons reciprocating in the cylinders insynchronization with the vanes, a mechanism is necessary for convertingreciprocating motion of the pistons to rotational motion of the rotor(e.g., a crank mechanism or a swash plate mechanism), and theconfiguration of the device is entirely complicated, resulting in alarger size and weight.

Further, Japanese Patent Application Laid-open No. 57-16293 disclosesthat the roller placed at the midpoint between the vanes is guided whilebeing engaged to the roller track placed in the casing. The vane onlygenerates load in a circumferential direction but does not generate loadin a radius direction. Hence, the engagement between the roller and theroller track does not contribute to conversion between mechanical energyand pressure energy of working fluid.

Moreover, Japanese Patent Application Laid-open No. 64-29676 disclosesthe radial plunger pump. Since the rotor is placed so as to be eccentricon the inside of the circular cam ring, unbalanced load is applied tothe rotation shaft and vibration occurs.

Therefore, in the rotating fluid machine comprising the pistons and thevanes that are placed on the rotor and are integrally moved, it isdesirable to smoothly convert mechanical energy and pressure energy ofworking fluid with a simple configuration, and to properly control a gapbetween the outer peripheral surface of the vane and the innerperipheral surface of the rotor chamber.

Hence, in the above described expander 4, the first energy conversionmeans formed by the cylinder members 39 and the pistons 41, and thesecond energy conversion means formed by the vanes 42 are provided onthe rotor 31, which is used in common. With cooperation of the first andsecond energy conversion means, energy of high-temperature high-pressurevapor is taken out to the output shaft 23 as mechanical energy. In thefirst energy conversion means formed by the cylinder members 39 and thepistons 41, the rollers 59 placed on the vane piston units U1 to U12 arerotatably engaged to the ring groove 60. The vane piston units U1 to U12reciprocate in a radial direction by the pistons 41. The ring groove 60is placed on the first and second half bodies 8 and 9 and issubstantially oval. Therefore, the reciprocating motion of the pistons41, that is, the reciprocating motion of the vane piston units U1 to U12is converted to rotational motion of the rotor 31 via the rollers 59 andthe ring grooves 60. In this way, since the rollers 59 and the ringgroove 60 are used, it is necessary to eliminate the necessity for acomplicated and large crank mechanism and swash plate mechanism forconverting the reciprocating motion to a rotational motion, to simplifythe configuration of the expander 4 with a compact configuration, and tominimize energy loss resulting from friction.

Moreover, the second energy conversion means formed by the vanes 42 canefficiently process a large quantity of vapor with quite a simpleconfiguration in which the rotor 31 is rotated in response to pressureof the first low-temperature low-pressure vapor being reduced intemperature and pressure by the first energy conversion means. And then,mechanical energy output by the first energy conversion means, which isoperated by high-temperature high-pressure vapor, and mechanical energyoutput by the second energy conversion means, which is operated by thefirst low-temperature low-pressure vapor, are combined and output.Hence, it is possible to fully use energy of original high-temperaturehigh-pressure vapor so as to improve efficiency of converting energy ofthe expander 4.

Moreover, when the vane piston units U1 to U12 reciprocate in a radialdirection relative to the rotor 31, the rollers 59 placed in the vanepiston units U1 to U12 are guided by the ring grooves 60. Hence, it ispossible to maintain a constant gap between the outer peripheral surfaceof the vane 42 and the inner peripheral surface of the rotor chamber 14.Additionally, the sealing effect between the vane body 43 and the innerperipheral surface the rotor chamber 14 is generated by spring force ofthe seal member 44, centrifugal force applied to the seal member 44, andvapor pressure generated by vapor which enters the U-shaped grooves 52of the vane main bodies 43 from the rotor chamber 14 on a high-pressureside and which presses upward the seal member 44. Hence, the sealingeffect is not affected by excessive centrifugal force applied to thevane body 43 according to the number of revolutions of the rotor 31, itis possible to always achieve compatibility between fine sealingproperty and low friction, and it is possible to prevent the occurrenceof abnormal friction and friction loss, which result from excessivecontact pressure caused by centrifugal force of the vane body 43 betweenthe vane 42 and the rotor chamber 14. Further, it is possible tominimize the occurrence of leakage of vapor from a gap of the vane 42and the rotor chamber 14.

Moreover, the rotation axis line L of the rotor 31 (that is, therotation axis line L of the output shaft 23) conforms to the center ofthe rotor chamber 14, and when the rotor 31 is divided into fourlongitudinally and laterally by 90° in FIGS. 17 and 18, pressure energyis converted to mechanical energy on the upper right quadrant and thelower left quadrant, which are point symmetric with respect to therotation axis line L. Thus, it is possible to prevent unbalanced loadfrom being applied to the rotor 31, thereby suppressing the occurrenceof vibration.

Namely, the rotating fluid machine comprises at least the first energyconversion means and the second energy conversion means, inputs workingfluid having pressure energy to the first and second energy conversionmeans to convert the pressure energy to mechanical energy, so that therotating fluid machine can function as an expander for combiningmechanical energy generated by the first and second conversion means andoutputting the energy, and besides, the rotating fluid machine inputsmechanical energy to the first and second energy conversion means toconvert the mechanical energy to pressure energy of working fluid, sothat the rotating fluid machine can function as a compressor forcombining pressure energy of the working fluid that is generated by thefirst and second energy conversion means and outputting the energy. Thefirst energy conversion means is formed by the cylinders which areformed radially on the rotor rotatably stored in the rotor chamber, andthe pistons which slide in the cylinders. The second energy conversionmeans is formed by the vanes which appear in a radial direction from therotor and have the outer peripheral surfaces sliding on the innerperipheral surface of the rotor chamber. In the above rotating fluidmachine, at least the rollers operating in synchronization with thepistons are provided, and the roller are engaged to the noncircular ringgroove formed on the casing for dividing the rotor chambers, so that thereciprocating motion of the pistons and the rotational motion of therotor are converted to each other.

According to the above described sixth arrangement, the rollers areprovided which rotate in the rotor chamber and are operated insynchronization with the pistons moving at least in a radial directionof the rotor, and the rotors are engaged into the noncircular ringgroove formed on the casing for dividing the rotor chamber. Thus, with asimple configuration formed by the rollers and the ring groove, in thecase of the function as an expander, reciprocating motion of the pistonscan be converted to rotation motion of the rotor, and in the case of thefunction of a compressor, rotation motion of the rotor can be convertedto reciprocating motion of the pistons.

Further, the rotating fluid machine comprises at least the first energyconversion means and the second energy conversion means, and inputsworking fluid having pressure energy to the first and second energyconversion means to convert the pressure energy to mechanical energy, sothat the rotating fluid machine can function as an expander forcombining mechanical energy generated by the first and second energyconversion means and outputting the energy, and besides, the rotatingfluid machine inputs mechanical energy to the first and second energyconversion means to convert the mechanical energy to pressure energy ofworking fluid, so that the rotating fluid machine can function as acompressors for combining pressure energy of working fluid that isgenerated by the first and second energy conversion means and outputtingthe energy. The first energy conversion means is formed by the cylinderswhich are formed radially on the rotor rotatably stored in the rotorchamber, and the pistons which slide in the cylinders. The second energyconversion means is formed by the vanes which appear in a radialdirection from the rotor and have the outer peripheral surfaces slidingon the inner peripheral surface of the rotor chamber. In the aboverotating fluid machine, at least the rollers are provided which areoperated in synchronization with the vanes, and the rollers are engagedto the noncircular ring groove formed in the casing for dividing therotor chamber so as to regulate a gap between the outer peripheralsurface of the vane and the inner peripheral surface of the rotorchamber.

According to the above described seventh arrangement, the rollers areprovided which rotate in the rotor chamber and move at least in a radialdirection relative to the rotor and operate in synchronization with thevane, and the rollers are engaged to the noncircular ring groove formedon the casing for dividing the rotor chamber. Thus, by guiding thetraveling track of the rollers with the ring groove it is possible toregulate a gap between the outer peripheral surface of the vane and theinner peripheral surface of the rotor chamber so as to prevent theoccurrence of abnormal abrasion and the occurrence of leakage.

Also, the rotating fluid machine comprises at least the first energyconversion means and the second energy conversion means, inputs workingfluid having pressure energy to the first and second energy conversionmeans to convert the pressure energy to mechanical energy, so that therotating fluid machine can function as an expander for combiningmechanical energy generated by the first and second energy conversionmeans and outputting the energy, and besides, the rotating fluid machineinputs mechanical energy to the first and second energy conversion meansto convert the mechanical energy to pressure energy of working fluid, sothat the rotating fluid machine can function as a compressor forcombining generated pressure energy of working fluid that is generatedby the first and second energy conversion means and outputting theenergy. The first energy conversion means is formed by the cylinderswhich are formed radially on the rotor rotatably stored in the rotorchamber, and the pistons which slide in the cylinders, and the secondenergy conversion means is formed by the vanes which appear in a radialdirection from the rotor and have the outer peripheral surfaces slidingon the inner peripheral surface of the rotor chamber. In the aboverotating fluid machine, the rollers are provided which are operated insynchronization with the vanes and the pistons, and the rollers areengaged to the noncircular ring groove formed on the casing for dividingthe rotor chamber, so that the reciprocating motion of the pistons andthe rotation motion of the rotor can be converted to each other, and thea gap between the outer peripheral surface of the vane and the innerperipheral surface of the rotor chamber is regulated.

According to the above described eighth arrangement, the vanes areprovided which rotate in the rotor chamber and move at least in a radialdirection relative to the rotor, and the rollers operating insynchronization with the pistons, and the rollers are engaged to thenoncircular ring groove formed on the casing for dividing the rotorchamber. Thus, with a simple configuration formed by the rollers and thering groove, in the case of the function as an expander, thereciprocating motion of the pistons can be converted to the rotationmotion of the rotor, and in the case of the function as a compressor,the rotation motion of the rotor can be converted to the reciprocatingmotion of the pistons. Additionally, the traveling track of the rolleris guided by the ring groove, so that a gap between the outer peripheralsurface of the vane and the inner peripheral surface of the rotorchamber can be regulated to prevent the occurrence of abnormal abrasionand the occurrence of leakage.

Moreover, in addition to any of the sixth to eighth arrangements, therotation shaft of the rotor conforms to the center of the rotor chamber.

According to the above described ninth arrangement, since the rotationshaft of the rotor conforms to the center of the rotor chamber, it ispossible to prevent unbalanced load from being applied to the rotor soas to prevent vibration caused by the rotation of the rotor.

It should be noted here that, as to high-temperature high-pressure vaporsupplied to the vane-type rotating machine, which functions as anexpander, a temperature and a pressure are reduced as pressure energy(thermal energy) is converted to mechanical energy by the vanes.Meanwhile, in the vane-type rotating machine which functions as acompressor, working fluid, which is compressed by the vanes driven bymechanical energy, gradually increases in temperature and pressure.

Therefore, in the case where a plurality of rotating machines are placedinside and outside in a radius direction, when low-pressure workingfluid is supplied to the inner rotating machine and high-pressureworking fluid is supplied to the outer rotating machine, a pressure ofthe working fluid is consumed needlessly because the high-pressureworking fluid is more likely to leak to the outside of the casing.Further, in the case where a plurality of rotating machines are placedinside and outside in a radius direction, when low-temperature workingfluid is supplied to the inner rotating machine, and thehigh-temperature working fluid is supplied to the outer rotatingmachine, thermal efficiency is reduced because heat of the working fluidis likely to leak to the outside of the casing.

Therefore, in the rotating fluid machine having at least the firstenergy conversion means and the second energy conversion means placedinside and outside in a radius direction, it is desirable to minimizeleakage of heat and pressure of working fluid to improve efficiency ofthe rotating fluid machine.

Thus, in the above described expander 4, the first energy conversionmeans formed by the cylinder members 39 and the pistons 41 is placed atthe center of the rotor chamber 14, and the second energy conversionmeans formed by the vanes 42 is placed outside in a radius direction soas to surround the first energy conversion means. Therefore,high-temperature high-pressure vapor is initially supplied to the firstenergy conversion means (cylinders 39 and pistons 41) at the center, andthe first low-temperature low-pressure vapor, which has been convertedto mechanical energy in the first energy conversion means, is suppliedto the second energy conversion means (vanes 42) on the outer peripheralsurface. In this way, when the first and second energy conversion meansare placed inside and outside in a radius direction, high-temperaturehigh-pressure vapor is supplied to the inner first energy conversionmeans, and low-temperature low-pressure vapor is supplied to the outsidesecond energy conversion means, so that pressure and heat ofhigh-temperature high-pressure vapor leaked from the inner first energyconversion means can be captured and recovered by the outer secondenergy conversion means, and leaked high-temperature high-pressure vaporcan be used without wasting the vapor to improve overall efficiency ofthe expander 4. Additionally, the second energy conversion means, whichsupplies the first low-temperature low-pressure vapor with a relativelylow pressure and temperature, is placed on the outer peripheral surfaceof the rotor chamber 14. Hence, sealing can be readily made to preventleakage of working fluid to the outside from the rotor chamber 14.Additionally, thermal insulation can be also readily made to preventleakage of heat to the outside from the rotor chamber 14.

Besides, when the rotating fluid machine of the present invention isused as a compressor, compressed air, which is compressed by first-statecompression of the vanes 42 serving as the outer second energyconversion means, increases in pressure and temperature, and thecompressed air further increases in pressure and temperature bysecond-stage compression of the cylinder means 39 and the pistons 41that serve as the inner first energy conversion means. Therefore, evenwhen the rotating fluid machine is used as a compressor, it is possibleto cause the outer second energy conversion means to capture and recoverpressure and heat of high-temperature high-pressure compressed airleaked from the inner first energy conversion means so as to improveoverall efficiency of the compressor. Additionally, sealing can bereadily made to prevent leakage of compressed air to the outside fromthe rotor chamber 14, and thermal insulation can be also readily made toprevent leakage of heat to the outside from the rotor chamber 14.

Namely, the rotating fluid machine comprises at least the first energyconversion means and the second energy conversion means, and inputsworking fluid having pressure energy to the first and second energyconversion means to convert the pressure energy to mechanical energy, sothat the rotating fluid machine can function as an expander forcombining mechanical energy generated by the first and second energyconversion means and outputting the energy, and besides, the rotatingfluid machine inputs mechanical energy to the first and second energyconversion means to convert the mechanical energy to pressure energy ofworking fluid, so that the rotating fluid machine can function as acompressor for combining pressure energy of the working fluid that isgenerated by the first and second energy conversion means and outputtingthe energy. In the above rotating fluid machine, high-pressure workingfluid is placed at the center of the rotor chamber for rotatably storingthe rotor having the first and the second energy conversion means, andlow-pressure working fluid is placed on the outer circumference of therotor chamber.

According to the above described tenth arrangement, high-pressureworking fluid and low-pressure working fluid are respectively placed atthe center and the outer circumference of the rotor chamber, whichrotatably stores the rotor. Hence, high-pressure working fluid leakedfrom the center of the rotor chamber is captured and recovered bylow-pressure working fluid on the outer circumference of the rotorchamber, the leaked high-pressure working fluid can be used withoutwasting the fluid to improve overall efficiency of the rotating fluidmachine, and sealing can be readily made to prevent leakage of workingfluid to the outside from the rotor chamber.

Further, the rotating fluid machine comprises at least the first energyconversion means and the second energy conversion means, and inputsworking fluid having pressure energy to the first and second energyconversion means to convert the pressure energy to mechanical energy, sothat the rotating fluid machine can function as an expander forcombining mechanical energy generated by the first and second energyconversion means and outputting the energy, and besides, the rotatingfluid machine inputs mechanical energy to the first and second energyconversion means to convert the mechanical energy to pressure energy ofworking fluid, so that the rotating fluid machine can function as acompressor for combining pressure energy of working fluid that isgenerated by the first and second energy conversion means and outputtingthe energy. In the above rotating fluid machine, high-temperatureworking fluid is placed at the center of the rotor chamber for rotatablystoring the rotor having the first and second energy conversion means,and low-temperature working fluid is placed on the outer circumferenceof the rotor chamber.

According to the eleventh arrangement, high-temperature working fluidand low-temperature working fluid are respectively placed at the centerand the outer circumference of the rotor chamber for rotatably storingthe rotor. Hence, high-temperature working fluid leaked from the centerof the rotor chamber is captured and recovered by low-temperatureworking fluid on the outer circumference of the rotor chamber, theleaked high-temperature working fluid can be used without waste toimprove overall efficiency of the rotating fluid machine, and thermalinsulation can be readily made to prevent leakage of heat to the outsidefrom the rotor chamber.

Moreover, the rotating fluid machine comprises at least the first energyconversion means and the second energy conversion means, and inputsworking fluid having pressure energy to the first and second energyconversion means to convert the pressure energy to mechanical energy, sothat the rotating fluid machine can function as an expander forcombining mechanical energy generated by the first and second energyconversion means and outputting the energy, and besides, the rotatingfluid machine inputs mechanical energy to the first and second energyconversion means to convert the mechanical energy to pressure energy ofworking fluid, so that the rotating fluid machine can function as acompressor for combining pressure energy of working fluid that isgenerated by the first and second energy conversion means and outputtingthe energy. In the above rotating fluid machine, high-pressure andhigh-temperature working fluid is placed at the center of the rotorchamber for rotatably storing the rotor having the first and secondenergy conversion means, and low-temperature and low-pressure workingfluid is placed on the outer circumference of the rotor chamber.

According to the twelfth arrangement, high-pressure and high-temperatureworking fluid and low-pressure and low-temperature working fluid arerespectively placed at the center and the outer circumference of therotor chamber for rotatably storing the rotor. Thus, high-pressure andhigh-temperature working fluid leaked from the center of the rotorchamber is captured and recovered by low-pressure and low-temperatureworking fluid on the outer circumference of the rotor chamber, and theleaked high-pressure and high-temperature working fluid can be usedwithout waste to improve overall efficiency of the rotating fluidmachine. Besides, since low-pressure low-temperature working fluid isplaced on the outer circumference of the rotor chamber, sealing can bereadily made to prevent leakage of working fluid to the rotor chamber tothe outside, and heat insulation can be readily made to prevent leakageof heat to the outside from the rotor chamber.

Further, in addition to any of the tenth to twelfth arrangements, thefirst energy conversion means is formed by the cylinders which areformed radially on the rotor rotatably stored in the rotor chamber, andthe pistons which slide in the cylinder, and the second energyconversion means is formed by the vanes which appear in a radialdirection from the rotor and have the outer peripheral surfaces slidingon the inner peripheral surface of the rotor chamber.

According to the thirteenth arrangement, the first energy conversionmeans is formed by the cylinders which are radially formed on the rotorrotatably stored in the rotor chamber, and the pistons which slide inthe cylinders. Thus, sealing property of high-pressure working fluid canbe improved to minimize a reduction in efficiency that is caused byleakage, and the second energy conversion means is formed by the vaneswhich is supported by the rotor so as to freely move in a radialdirection and slide on the inner peripheral surface of the rotorchamber. Hence, the mechanism for converting pressure energy andmechanical energy can be simplified, and a large quantity of workingfluid can be processed with a compact configuration. In this way, withthe combination of the first energy conversion means having the pistonsand the cylinders and the second energy conversion means having thevanes, it is possible to obtain a high-performance rotating fluidmachine achieving compatibility of both of the means.

Incidentally, Japanese Patent Application Laid-open No. 58-48076discloses that a simple vane motor is used as an expander. Thus, it isdifficult to efficiently convert energy of high-temperaturehigh-pressure vapor generated by the evaporator to mechanical energy.

Therefore, it is desirable to improve efficiency of the expander of theRankine cycle device to efficiently convert energy of high-temperaturehigh-pressure vapor to mechanical energy.

Hence, in the Rankine cycle formed by the evaporator 3 for heating waterwith thermal energy of exhaust gas by the internal combustion engine 1to generate high-temperature high-pressure vapor, the expander 4 forconverting high-temperature high-pressure vapor to shaft output withconstant torque, the condenser 5 for liquefying low-temperaturelow-pressure vapor discharged by the expander 4, and the feed pump 6 forsupplying water liquefied by the condenser 5 to the evaporator 3, theabove described example adopts a displacement-type machine as theexpander 4. The displacement-type expander 4 can recover energy withhigh efficiency in a wide region of the number of revolutions from lowspeed to high speed, and the expander 4 is further excellent in trackingand response for variations in thermal energy (variations in temperatureand quantity of exhaust gas), the variations being caused by an increaseand decrease in the number of revolutions of the internal combustionengine 1. Furthermore, the expander 4 is a double expansion type, inwhich the first energy conversion means formed by the cylinder members39 and the pistons 41 and the second energy conversion means formed bythe vanes 42 are connected in series and are placed inside and outsidein a radius direction. Hence, it is possible to further improveefficiency of recovering thermal energy by using a Rankine cycle whilethe expander 4 is reduced in weight and size to improve spaceefficiency.

Namely, the rotating fluid machine is provided in the Rankine cycledevice which converts pressure energy of high-temperature high-pressurevapor to mechanical energy, the high-temperature high-pressure beinggenerated by heating water with waste heat of the prime mover, whichcondenses low-temperature low-pressure vapor generated thus and heat thevapor with the above waste heat again, and which is comprised of thedisplacement-type expander for converting pressure energy to mechanicalenergy. In the above rotating fluid machine, the expander comprises atleast the first energy conversion means and the second energy conversionmeans, and the pressure energy is input to the first and second energyconversion means to be converted to mechanical energy, so thatmechanical energies generated by the first and second energy conversionmeans are combined and output.

According to the above fourteenth arrangement, the Rankine cycle devicewhich converts pressure energy of high-temperature high-pressure vaporto mechanical energy, the high-temperature high-pressure vapor beinggenerated by heating water with waste heat of the prime mover, and whichliquefies low-temperature low-pressure vapor generated thus and heatsthe vapor with the above waste heat again. In such a Rankine cycledevice, the expander for converting pressure energy to mechanical energyis a displacement-type. Thus, as compared with an expander of anon-displacement-type such as a turbine, it is possible to recoverenergy with high efficiency in a wide region of the number ofrevolutions from low speed to high speed and to further improveefficiency of recovering thermal energy by using a Rankine cycle.Furthermore, the expander is excellent in tracking and response tovariations in energy of waste heat, the variations being caused by anincrease and decrease in the number of revolutions of the prime mover.Moreover, the displacement-type expander combines the output of thefirst energy conversion means and the output of the second energyconversion means and outputs the combined outputs. Thus, it is possibleto convert pressure energy of high-temperature high-pressure vapor tomechanical energy without wasting the energy, and it is also possible toreduce the expander in weight and size to improve space efficiency.

Moreover, in addition to the above fourteenth arrangement, the firstenergy conversion means is formed by the cylinders which are radiallyformed on the rotor rotatably stored in the rotor chamber, and thepistons which slide in the cylinders, and the second energy conversionmeans is formed by the vane which appear radially from the rotor andhave the outer circumference surfaces sliding on the inner peripheralsurface of the rotor chamber.

According to the above fifteenth arrangement, the first energyconversion means is formed by the cylinders which are formed radially onthe rotor rotatably stored in the rotor chamber, and the pistons whichslide in the cylinders. Hence, it is possible to improve the sealingproperty of high-pressure vapor to minimize a reduction in efficiencythat is caused by leakage. Besides, the second energy conversion meansis formed by the vanes which are movably supported in a radial directionon the rotor and slide on the inner peripheral surface of the rotorchamber. Thus, the configuration of the mechanism for convertingpressure energy and mechanical energy is simplified and a large flowrate of vapor can be processed with a compact configuration. In thisway, the first energy conversion means having the pistons and thecylinders and the second energy conversion means having the vanes arecombined, so that a high-performance rotating fluid machine can beobtained with the characteristics of both of the means.

Also, in addition to the above fifteenth arrangement, the rollers areprovided which are operated in synchronization with the vanes and thepistons, and the rollers are engaged to the noncircular ring grooveformed on the casing for dividing the rotor chamber, so that thereciprocating motion of the pistons and the rotation motion of the rotorare converted to each other, and a gap is regulated between the outerperipheral surface of the vane and the inner peripheral surface of therotor chamber.

According to the above sixteenth arrangement, the rollers are providedwhich are operated in synchronization with the vanes and the pistons.The vanes and the pistons move in a radial direction at least relativeto the rotor, which rotates in the rotor chamber. The rollers areengaged to the noncircular ring groove formed on the casing for dividingthe rotor chamber. Thus, with a simple configuration including therollers and the ring groove, the reciprocating motion of the pistons canbe converted to the rotational motion of the rotor, and the travelingtrack of the roller is guided by the ring groove, so that it is possibleto regulate a gap between the outer peripheral surface of the vane andthe inner peripheral surface of the rotor chamber to prevent theoccurrence of normal abrasion and the occurrence of leakage.

Further, in addition to the above fourteenth arrangement,high-temperature high-pressure vapor is placed at the center of therotor chamber for rotatably storing the rotor, which comprises the firstand second energy conversion means, and low-temperature low-pressurevapor is placed on the outer peripheral surface of the rotor chamber.

According to the above seventeenth arrangement, high-temperaturehigh-pressure vapor and low-temperature low pressure vapor are placed atthe center and the outer circumference of the rotor chamber forrotatably storing the rotor. Hence, high-temperature high-pressure vaporleaked from the center of the rotor chamber is captured and recovered bylow-temperature low-pressure vapor on the outer circumference of therotor chamber, and the leaked high-temperature high-pressure vapor canbe used without wasting the vapor to improve overall efficiency of therotating fluid machine. In addition, since low-temperature low-pressurevapor is placed on the outer circumference of the rotor chamber, sealingcan be readily made to prevent leakage of vapor from the rotor chamberto the outside, and thermal insulation can be readily made to preventleakage of heat from the rotor chamber to the outside.

Further, in addition to the above seventeenth arrangement, the firstenergy conversion means is formed by the cylinders which are formedradially on the rotor rotatably stored in the rotor chamber, and thepistons which slide in the cylinders, and the second energy conversionmeans is formed by the vanes which appear radially from the rotor andhave outer peripheral surfaces sliding on the inner peripheral surfaceof the rotor chamber.

According to the above eighteenth arrangement, the first energyconversion means is formed by the cylinders which are formed radially onthe rotor rotatably stored in the rotor chamber, and the pistons whichslide in the cylinders. Hence, it is possible to improve the sealingproperty of high-pressure vapor to minimize a reduction in efficiencythat is caused by leakage. Further, the second energy conversion meansis formed by the vanes which are movably supported on the rotor in aradial direction and slide on the inner peripheral surface of the rotorchamber. Thus, the configuration of the mechanism for convertingpressure energy and mechanical energy is simplified, and a large flowrate of vapor can be processed with a compact configuration. In thisway, with the combination of the first energy conversion means havingthe pistons and the cylinders and the second energy conversion meanshaving the vanes, a high-performance rotating fluid machine can beobtained with the characteristics of both of the means.

Although the embodiment of the present invention has been described indetail, it will be understood that the present invention is not limitedto the above-described embodiment, and various modifications in designmay be made without departing from the subject matter of the inventiondefined in the claims.

For example, in the above embodiment, water is shown as an example ofworking medium. A working medium other than water is also applicable.

Moreover, in the above embodiment, the drive system for driving anautomobile is shown as an example. Like auxiliary machinery including apump and fan, the present invention can be applied to a drive systemused for the other arbitrary purposes.

Further, in the above embodiment, the power generator/motor 124 and thetransmission 143 are shown as examples of a portion driven by theexpander 4.

Besides, in the expander 4 of the above embodiment, afterhigh-temperature high-pressure vapor is initially supplied to thecylinder members 39 and the pistons 41 that serve as the first energyconversion means, the first low-temperature low-pressure vapor reducedin temperature and pressure is supplied to the vanes 42 serving as thesecond energy conversion means. For example, the following configurationis also applicable: connection or disconnection is made between thethrough-hole t, which discharges the first low-temperature low-pressurevapor from the first energy conversion means shown in FIG. 15, and therelay chamber 20, and means is provided for supplying vapor separatelyto the relay chamber 20 via the shell-shaped member 16 separately fromthe second energy conversion means, so that vapor is separately suppliedto the first and second energy conversion means with differenttemperatures and pressures.

Further, vapor may be separately supplied to the first and second energyconversion means with different temperatures and pressures, and vaporreduced in temperature and pressure after passage through the firstenergy conversion means may be additionally supplied to the secondenergy conversion means.

Moreover, in the above embodiment, the rollers 59 are provided on thevane main bodies 43 of the vane piston units U1 to U12. The rollers 59may be provided on parts other than the vane piston units U1 to U12, forexample, on the piston 41.

INDUSTRIAL APPLICABILITY

As described above, the drive system according to the present inventioncan be suitably used as a driving source of an automobile but is alsoapplicable to a driving source of auxiliary machinery of an automobilethat includes a pump and fan. Further, it is also applicable to a drivesystem used for an arbitrary purpose other than an automobile.

What is claimed is:
 1. A drive system comprising: a waste heatrecovering device forming a Rankine cycle by an evaporator for heating aworking medium with waste heat of a prime mover to generatehigh-pressure vapor, a displacement-type expander for convertinghigh-pressure vapor generated by the evaporator to output with aconstant torque, a condenser for liquefying low-pressure vapordischarged from the expander, and a pump for supplying the workingmedium liquefied by the condenser to the evaporator; and a powertransmission system having a variable change gear ratio and capable ofconducting a speed change operation for transmitting an output of theexpander to a driven portion, said power transmission system driving thedriven portion according to output characteristics of the expander. 2.The drive system according to claim 1, wherein said power transmissionsystem drives the driven portion within a range of the outputcharacteristics of the expander.
 3. The drive system according to claim1, wherein said power transmission system can distribute the output ofthe expander to a plurality of driven portions in an arbitrary ratio. 4.The drive system according to claim 3, wherein the plurality of driveportions includes a power generator and a transmission.
 5. A drivesystem according to claim 1, wherein said power transmission systemcomprises at least a planetary gear mechanism.
 6. The drive systemaccording to claim 5, wherein the planetary gear mechanism includes asun gear, a ring gear, and a planetary carrier, and by fixing one of thesun gear, the ring gear, and the planetary carrier, transmission ofdriving force can be switched among the expander and a plurality ofdriven portions.